regmap: maple: Use alloc_flags for memory allocations
Commit Message
REGCACHE_MAPLE needs to allocate memory for regmap operations.
This results in lockdep splats if used with fast_io since fast_io uses
spinlocks for locking.
BUG: sleeping function called from invalid context at include/linux/sched/mm.h:306
in_atomic(): 1, irqs_disabled(): 128, non_block: 0, pid: 167, name: kunit_try_catch
preempt_count: 1, expected: 0
1 lock held by kunit_try_catch/167:
#0: 838e9c10 (regmap_kunit:86:(config)->lock){....}-{2:2}, at: regmap_lock_spinlock+0x14/0x1c
irq event stamp: 146
hardirqs last enabled at (145): [<8078bfa8>] crng_make_state+0x1a0/0x294
hardirqs last disabled at (146): [<80c5f62c>] _raw_spin_lock_irqsave+0x7c/0x80
softirqs last enabled at (0): [<80110cc4>] copy_process+0x810/0x216c
softirqs last disabled at (0): [<00000000>] 0x0
CPU: 0 PID: 167 Comm: kunit_try_catch Tainted: G N 6.5.0-rc1-00028-gc4be22597a36-dirty #6
Hardware name: Generic DT based system
unwind_backtrace from show_stack+0x18/0x1c
show_stack from dump_stack_lvl+0x38/0x5c
dump_stack_lvl from __might_resched+0x188/0x2d0
__might_resched from __kmem_cache_alloc_node+0x1f4/0x258
__kmem_cache_alloc_node from __kmalloc+0x48/0x170
__kmalloc from regcache_maple_write+0x194/0x248
regcache_maple_write from _regmap_write+0x88/0x140
_regmap_write from regmap_write+0x44/0x68
regmap_write from basic_read_write+0x8c/0x27c
basic_read_write from kunit_generic_run_threadfn_adapter+0x1c/0x28
kunit_generic_run_threadfn_adapter from kthread+0xf8/0x120
kthread from ret_from_fork+0x14/0x3c
Exception stack(0x881a5fb0 to 0x881a5ff8)
5fa0: 00000000 00000000 00000000 00000000
5fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
5fe0: 00000000 00000000 00000000 00000000 00000013 00000000
Use map->alloc_flags instead of GFP_KERNEL for memory allocations to fix
the problem.
Fixes: f033c26de5a5 ("regmap: Add maple tree based register cache")
Cc: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
drivers/base/regmap/regcache-maple.c | 16 ++++++++--------
1 file changed, 8 insertions(+), 8 deletions(-)
Comments
On Thu, 20 Jul 2023 10:20:21 -0700, Guenter Roeck wrote:
> REGCACHE_MAPLE needs to allocate memory for regmap operations.
> This results in lockdep splats if used with fast_io since fast_io uses
> spinlocks for locking.
>
> BUG: sleeping function called from invalid context at include/linux/sched/mm.h:306
> in_atomic(): 1, irqs_disabled(): 128, non_block: 0, pid: 167, name: kunit_try_catch
> preempt_count: 1, expected: 0
> 1 lock held by kunit_try_catch/167:
> #0: 838e9c10 (regmap_kunit:86:(config)->lock){....}-{2:2}, at: regmap_lock_spinlock+0x14/0x1c
> irq event stamp: 146
> hardirqs last enabled at (145): [<8078bfa8>] crng_make_state+0x1a0/0x294
> hardirqs last disabled at (146): [<80c5f62c>] _raw_spin_lock_irqsave+0x7c/0x80
> softirqs last enabled at (0): [<80110cc4>] copy_process+0x810/0x216c
> softirqs last disabled at (0): [<00000000>] 0x0
> CPU: 0 PID: 167 Comm: kunit_try_catch Tainted: G N 6.5.0-rc1-00028-gc4be22597a36-dirty #6
> Hardware name: Generic DT based system
> unwind_backtrace from show_stack+0x18/0x1c
> show_stack from dump_stack_lvl+0x38/0x5c
> dump_stack_lvl from __might_resched+0x188/0x2d0
> __might_resched from __kmem_cache_alloc_node+0x1f4/0x258
> __kmem_cache_alloc_node from __kmalloc+0x48/0x170
> __kmalloc from regcache_maple_write+0x194/0x248
> regcache_maple_write from _regmap_write+0x88/0x140
> _regmap_write from regmap_write+0x44/0x68
> regmap_write from basic_read_write+0x8c/0x27c
> basic_read_write from kunit_generic_run_threadfn_adapter+0x1c/0x28
> kunit_generic_run_threadfn_adapter from kthread+0xf8/0x120
> kthread from ret_from_fork+0x14/0x3c
> Exception stack(0x881a5fb0 to 0x881a5ff8)
> 5fa0: 00000000 00000000 00000000 00000000
> 5fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
> 5fe0: 00000000 00000000 00000000 00000000 00000013 00000000
>
> [...]
Applied to
https://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap.git for-next
Thanks!
[1/1] regmap: maple: Use alloc_flags for memory allocations
commit: b0393e1fe40e962574613a5cdc4a470d6c1de023
All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.
You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.
If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.
Please add any relevant lists and maintainers to the CCs when replying
to this mail.
Thanks,
Mark
@@ -74,7 +74,7 @@ static int regcache_maple_write(struct regmap *map, unsigned int reg,
rcu_read_unlock();
entry = kmalloc((last - index + 1) * sizeof(unsigned long),
- GFP_KERNEL);
+ map->alloc_flags);
if (!entry)
return -ENOMEM;
@@ -92,7 +92,7 @@ static int regcache_maple_write(struct regmap *map, unsigned int reg,
mas_lock(&mas);
mas_set_range(&mas, index, last);
- ret = mas_store_gfp(&mas, entry, GFP_KERNEL);
+ ret = mas_store_gfp(&mas, entry, map->alloc_flags);
mas_unlock(&mas);
@@ -134,7 +134,7 @@ static int regcache_maple_drop(struct regmap *map, unsigned int min,
lower = kmemdup(entry, ((min - mas.index) *
sizeof(unsigned long)),
- GFP_KERNEL);
+ map->alloc_flags);
if (!lower) {
ret = -ENOMEM;
goto out_unlocked;
@@ -148,7 +148,7 @@ static int regcache_maple_drop(struct regmap *map, unsigned int min,
upper = kmemdup(&entry[max + 1],
((mas.last - max) *
sizeof(unsigned long)),
- GFP_KERNEL);
+ map->alloc_flags);
if (!upper) {
ret = -ENOMEM;
goto out_unlocked;
@@ -162,7 +162,7 @@ static int regcache_maple_drop(struct regmap *map, unsigned int min,
/* Insert new nodes with the saved data */
if (lower) {
mas_set_range(&mas, lower_index, lower_last);
- ret = mas_store_gfp(&mas, lower, GFP_KERNEL);
+ ret = mas_store_gfp(&mas, lower, map->alloc_flags);
if (ret != 0)
goto out;
lower = NULL;
@@ -170,7 +170,7 @@ static int regcache_maple_drop(struct regmap *map, unsigned int min,
if (upper) {
mas_set_range(&mas, upper_index, upper_last);
- ret = mas_store_gfp(&mas, upper, GFP_KERNEL);
+ ret = mas_store_gfp(&mas, upper, map->alloc_flags);
if (ret != 0)
goto out;
upper = NULL;
@@ -320,7 +320,7 @@ static int regcache_maple_insert_block(struct regmap *map, int first,
unsigned long *entry;
int i, ret;
- entry = kcalloc(last - first + 1, sizeof(unsigned long), GFP_KERNEL);
+ entry = kcalloc(last - first + 1, sizeof(unsigned long), map->alloc_flags);
if (!entry)
return -ENOMEM;
@@ -331,7 +331,7 @@ static int regcache_maple_insert_block(struct regmap *map, int first,
mas_set_range(&mas, map->reg_defaults[first].reg,
map->reg_defaults[last].reg);
- ret = mas_store_gfp(&mas, entry, GFP_KERNEL);
+ ret = mas_store_gfp(&mas, entry, map->alloc_flags);
mas_unlock(&mas);